st-osc_10_11_12-20200418-66520e1.patch

Source: https://st.suckless.org/patches/osc_10_11_12/

This patch adds support for OSC escape sequences 10, 11 and 12,
that modify the bg, fg and cursor colors. To decouple them from
the palette you can select entries from the colorname table after
the 255 position for defaultfg, defaultbg and defaultcs.

Original author:
    Christian Tenllado - <ctenllado at gmail dot com>

Changelog:
    * Fixed bg flicker when setting both 0 and bg.

---
diff --git a/config.def.h b/config.def.h
index 6f05dce..a4f021e 100644
--- a/config.def.h
+++ b/config.def.h
@@ -129,8 +129,8 @@ static const char *colorname[] = {
  */
 unsigned int defaultfg = 7;
 unsigned int defaultbg = 0;
-static unsigned int defaultcs = 256;
-static unsigned int defaultrcs = 257;
+unsigned int defaultcs = 256;
+unsigned int defaultrcs = 257;

 /*
  * Default shape of cursor
diff --git a/st.c b/st.c
index 76b7e0d..6898aae 100644
--- a/st.c
+++ b/st.c
@@ -1870,12 +1870,23 @@ strhandle(void)
 			}
 			return;
 		case 4: /* color set */
-			if (narg < 3)
+		case 10: /* foreground set */
+		case 11: /* background set */
+		case 12: /* cursor color */
+			if ((par == 4 && narg < 3) || narg < 2)
 				break;
-			p = strescseq.args[2];
+			p = strescseq.args[((par == 4) ? 2 : 1)];
 			/* FALLTHROUGH */
 		case 104: /* color reset, here p = NULL */
-			j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
+			if (par == 10)
+				j = defaultfg;
+			else if (par == 11)
+				j = defaultbg;
+			else if (par == 12)
+				j = defaultcs;
+			else
+				j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
+
 			if (xsetcolorname(j, p)) {
 				if (par == 104 && narg <= 1)
 					return; /* color reset without parameter */
@@ -1886,7 +1897,9 @@ strhandle(void)
 				 * TODO if defaultbg color is changed, borders
 				 * are dirty
 				 */
-				redraw();
+                if (j != 0 && j != 15) {
+                    redraw();
+                }
 			}
 			return;
 		}
diff --git a/st.h b/st.h
index 3d351b6..054366d 100644
--- a/st.h
+++ b/st.h
@@ -123,3 +123,4 @@ extern char *termname;
 extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
+extern unsigned int defaultcs;